How to Identify a Common Grackle

What Does a Common Grackle Look Like?

Courtesy Stuart Fiedler

At a glance, many birders might confuse a common grackle for other black birds, including European starlings, red-winged blackbirds or American crows. Look closer, however, at these robin-sized birds, and you’ll spot a number of differences. If you’re lucky, you might even catch the colorful sheen that lends the common grackle an uncommon beauty.

“They have an iridescence to them,” David Wiedenfeld, senior conservation scientist with the American Bird Conservancy, explains. He also points out that there are differing common grackle subtypes in the United States, including those with a purple sheen and a bronze sheen. “It’s usually easiest to see [the shiny feathers] if you’re above them and looking down, so you can get light shining down on them,” David says.

Other identifying traits of a common grackle include a pointy bill, a long tail, and blue-black head feathers. Catch a good enough glimpse through binoculars or up close, and you’ll also spot yellow eyes.

Learn all about the different types of grackles in North America.

Common Grackle Range and Habitat

Courtesy Katie Wanner

Finding a common grackle shouldn’t be too difficult for U.S. birders, especially during warmer months. They’re abundant throughout most of the East, South, and Midwest.

Note that in the southern and western states, you might see boat-tailed grackles and great-tailed grackles.

Some common grackles spend spring and summer in the northern parts of their range before migrating back to southern states in the fall, although David notes that some don’t migrate at all. The ones that do, however, tend to be among the first arrivals. “They are some of our earliest migrants and earlier breeding birds,” David says.

While backyard birders can locate common grackles at their feeders, a sure bet for finding one is to search in agricultural fields. Grackles tend to eat cast-off seeds, and they’ll pick through to find corn or other kinds of grain. Because they roost together and form flocks in winter, farm fields will often fill with these birds. “You’ll sometimes see an agricultural field that’ll have 1,000 or even 50,000 grackles,” David explains.

Nesting Habits

Courtesy Michael Brozek

Grackles have one or two broods per nesting season, with a typical clutch size of four to five eggs. Females build nests in trees or shrubs, often near water, and sometimes in colonies with other grackles. “Their nest is a messy-looking, open cup,” David says. “They don’t do anything that’s neat.”

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Diet: What Do Common Grackles Eat?

Courtesy Misti Messemer

Common grackles aren’t picky eaters, to the chagrin of backyard birders who might rather they didn’t take feeders by storm. They’ll eat everything from acorns and sunflower seeds to insects and lizards depending on the time of year and resources available. They may also take food away from other birds.

For anyone looking to discourage them, David recommends caged bird feeders with openings too small for grackles to get through, or weighted perches. There are also other bird-safe methods people can use to safely stop them from perching.

Common Grackle Calls and Sounds

One who’s heard a common grackle won’t soon forget it — and not because they’re awed by the beauty of its song. “They’re very loud and not melodic,” David says. “There’s no melody you can follow.”

Grackles give screechy, loud calls that sound almost mechanical; when they’re gathered with dozens or hundreds in a group and making noise, the racket can be considered unpleasant.

Bird sounds courtesy of the Cornell Lab of Ornithology 

Common Grackle Population Numbers

Courtesy George Decamp

While common grackles aren’t a favorite bird of many, it’s important to note that their numbers have been decreasing. According to the National Audubon Society, populations have dwindled by 78% since 1970. To hear David tell it, one likely reason is a common foe for nature: pesticides.

Neonicotinoid pesticides are used in farming as a way of keeping insects from eating crops. When birds eat leftover grains, they can suffer side effects like reduced reproductive rates, weight loss, illness, and, if enough pesticides are consumed, death. Worse, the pesticides aren’t just found in grains. “Neonicotinoids are water-soluble, and they can become systemic in plants,” David explains. “The insects that eat the plants pick up some of it, and then birds eat them.”

If you want to help grackles and other birds, it’s a good reminder to limit pesticide use in your garden — especially avoid anything that might contain neonicotinoids.

And if you see a common grackle at your feeder, consider changing your mindset about black birds and letting it eat, instead of shooing it away.

About the Expert

As senior conservation scientist for American Bird Conservancy, David Wiedenfeld has worked on research pertaining to bird populations for decades. He served as director of research at the Sutton Avian Research Center, and he also served as head of the department of vertebrate ecology at the Charles Darwin Research Station in the Galapagos Islands. He holds a PhD in biological science from Florida State University, and his favorite bird is the swallow-tailed kite.

Sources

• Cornell Lab of Ornithology, “Common Grackle: Overview“
• Audubon, “Where Have All the Common Grackles Gone?“
• Audubon, “A Widespread Pesticide Causes Weight Loss and Delayed Migration in Songbirds“